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Sodium/Potassium Ratio Linked to Cardiovascular Disease Risk

Two nutrients, sodium and potassium, likely work together to affect blood pressure and heart disease risk, according to a new study.

Nearly 1 in 3 adult Americans has high blood pressure—defined
as 140/90 mmHg or higher—and about 37% have pre-hypertension,
which is defined as 120-139/80-89 mmHg. High blood pressure is
dangerous because it makes the heart work too hard and increases
the risk of cardiovascular diseases like heart disease and stroke,
the first- and third-leading causes of death nationwide.

In the past, researchers funded by NIH’s National Heart,
Lung and Blood Institute (NHLBI) showed that long-term interventions
to reduce sodium intake in people with prehypertension can lower
blood pressure and reduce the risk of cardiovascular disease.

The new Trials of Hypertension Prevention Follow-up Study involved
almost 3,000 participants who were 30 to 54 years old and had
prehypertension. Researchers collected urine intermittently during
24-hour periods over 18 months in one trial and 36 months in
another. They then compared the urinary levels of sodium and
potassium with subsequent cardiovascular diseases during 10 to
15 years of follow-up.

The results, published in the January 12, 2009, issue of the Archives
of Internal Medicine, showed a significant increase in
the risk of cardiovascular disease with higher ratios of sodium
to potassium. A high sodium/potassium ratio was a stronger
indicator of increased risk among the participants in the study
than levels of either sodium or potassium alone.

These results support previous findings that lowering dietary
sodium intake while increasing potassium intake can reduce the
incidence of cardiovascular disease. “This means that the
general population should eat foods low in sodium and high in
potassium,” says Dr. Eva Obarzanek of NHLBI’s Division
of Prevention and Population Studies, one of the study’s
co-authors.

Recent national nutrition surveys show that, on average, Americans
consume about 3300 mg of sodium per day (almost 1-1/2 tsp per
day of salt) and 2600 mg potassium per day. These are far from
the recommended goals of 2300 mg or less for sodium and 4700
mg or more for potassium. In fact, a recent report found that
only 13% of the population is meeting the sodium goal and well
below 5% is meeting the potassium goal.

“First and foremost, people need to read nutrition labels
on foods and choose foods that are low in sodium,” Obarzanek
says. “People can get accustomed to a lower sodium level
if they persist in consuming a diet low in sodium. Over time,
the taste and preference for salt decreases.”

You can boost your potassium intake by choosing more whole
unprocessed foods: fruits, vegetables, whole grains, fresh or
frozen meat, poultry and fish, and low-fat or non-fat milk products. These
foods tend to be low in sodium as well.